Cutting inserts particularly adapted for high cutting rate removal of relatively tough metals such as encountered in the turning of railway wheels has led to the development of tungsten carbide inserts with special cutting edges and faces directed to basic objects of increasing the rate of stock removal through greater depths of cuts, increased range of cutting feed rates with good chip control, as well as extending the useful life of each insert relative to the quantity of stock removal. In this regard standard indexable features have been employed and face configurations developed which will minimize power and heat dissipation requirements at the cutting edge.
As a result of concerted efforts by a number of competitive companies to continually improve performance of cutting inserts in these regards, a high degree of refinement of design has produced numerous insert styles having superficially similar appearance aspects.
Typical of the closest prior art inserts known to applicant are those produced by a Swedish company (Sandvikens Jernverks Aktiebolag) and sold under the trade mark "Sandvik Coromant T-Max P Tooling Inserts" examples of which are illustrated in a published brochure entitled "T-Max P Tool System for Railway Wheel Returning"; and cutting inserts disclosed in U.S. Pat. Nos. 3,973,307 and 3,421,196.
While such references teach various individual elements of applicant's improved insert construction there are a number of subtle but critical combinational distinctions which tests have proven to provide unexpected comparative results.